One thing that comes to mind right away is working for senior citizen complexes. They often need people to do some exercise for residents, many of whom are extremely able-bodied and want to remain so. Many have small fitness centers, run classes like "chair exercise" for those with a little less mobility but still needing muscle tone, and they also have things like walking clubs where people pick a route or a nature area or park and go walk for 90 minutes. Maybe they have some clerical work too, like staffing the reception desk and putting other programs together. Sometimes there is a complex with independent living, assisted living and nursing home all on the same campus, and they might have one full-time job made up of various half-time jobs, so you could still get benefits but split your time doing several things you are skilled at.
Gyms also need people to run classes as well as staff the front desk and even do some babysitting 2 hours per morning while the moms work out.
Smaller fitness centers sometimes have one owner who owns a few locations, and may have part time work at both, which could be melded into a full time job.
Finally, hospitals are always looking for staff and often running in-house fitness classes. If it wasn't full time in one area, perhaps it could be pieced together to make 40 hours with benefits.
Also, look into hospitals or other large companies who may be filling a temporary job, such as for someone on maternity leave. If they like you and you do a good job, you can often parlay that into a full time job in another department. I have an acquaintance with zero skills who managed that about 6 years ago, and she's still employed!